In these days, almost all human gene sequences have been analyzed, and a molecule having a specific function directed to a specific certain base sequence draws an attention of many researchers. For example, Dervan et al. discovered that a pyrrole (Py)-imidazole (Im) polyamide oriented in opposite directions was bonded to a minor group of a DNA in a base sequence-specific manner (Bioorg. Med. Chem. 2001, 9, 2215; Curr. Opin. Str. Biol. 1997, 7, 355; J. Am. Chem. Soc. 1997, 119, 7636 and the like). Since such a molecule has a binding constant and a specificity comparable with those of a transcription factor (J. Am. Chem. Soc. 1998, 120, 3534; J. Am. Chem. Soc. 1998, 120, 6219 and the like), it is employed actually in the investigation with regard to the control of a gene expression (Nature, 1997, 387, 202; Proc. Natl. Acad. Sci. USA 1998, 95, 12890 and the like). Nevertheless, the target sequences to which the polyamide is bonded are limited since the control of the gene expression is effected by means of the inhibition of the binding of the transcription factor (J. Am. Chem. Soc., 2000, 122, 4856).
The present inventors have previously developed and applied for patent a hybrid molecule 1 which is obtained by binding a segment A (Du) as an alkylation site of duocarmycin A to a Py-Im polyamide (WO00/15641). This hybrid molecule 1 has an ability of recognizing a sequence and alkylating one site in the DNA fragment of 450 base pairs by Py-Im polyamide (J. Am. Chem. Soc., 1999, 121, 4961). However, the reaction sequence-specific alkylation of a DNA by the molecule 1 takes 1 week or longer to complete, and its reaction efficiency is as low as 7%.

The present inventors also have discovered that an ImPyLDu86 (wherein L represents a vinyl linker; the same applies to the following description) inserted between the alkylation reaction site and the Py-Im polyamide forms a dimer to react specifically in a sequence of PyG(A/T) CPu at the both chains locating apart by 5 bases from each other (JP 2000-281679; J. Am. Chem. Soc. 2000, 122, 1602). At this time, the inventors made a change into the segment A of Du86 which is a cyclopropylindole (CPI) for the purpose of increasing the stability of the alkylating moiety. This compound was revealed to induce the alkylation in 70% of the ImPyLDu86 employed and allow the reactivity and the efficiency to be increased dramatically as a result of the introduction of the linker.